The present invention relates to eyewear and, more particularly, to a selectively attachable traction device for improving the retention of the eyewear about the head and a method for using the same.
While corrective lenses are specifically crafted to accommodate the unique vision defects of an individual, the frames used to retain the lenses are typically a standard size and not crafted to conform to the particular contours of an individual's head. Lenses which are employed in filtering eyewear such as sunglasses are also typically retained in stock frames. However, it is virtually impossible to mass produce stock frames which fit every individual's head; therefore, stock frames are constructed to conform to an idealized "standard" adult head.
As a result, such frames often result in a fit which is either too tight or too loose about the head of an individual. A tight fitting frame may cause localized pain and headaches, while a loose fitting frame may allow the eyewear to fall from the head and damage the frame or the lens. This is particularly disadvantageous for protective eyewear such as sunglasses which are to be used in active sports, such as bicycle racing or skiing. Additionally, in the event that corrective lenses vary in weight between the lenses, the uneven weight distribution may cause frames to locally abrade the skin.
A variety of means have been employed to improve the securing of eyewear to the head. These devices have included the use of loose strings which connect the temples of the eyewear around the back of the wearer's head, thereby preventing the glasses from becoming completely displaced from the body. Alternatively, an elastic strap connecting the temples has been employed to engage the wearer's head and secure the eyewear in the desired position.
Perhaps most frequently used, temples have been provided with a hook at the posterior end for engaging the wearer behind the ears. However, due to the significant variation among individuals in the distance from the appropriate position of an eyeglass lens and the back of the ear, the traditional ear hook is frequently either too far back or too far forward of the appropriate position on the wearer's ear. This causes either a painful or irritating friction if the hook is too far forward, or a loose fit if too far back.
The prior attempts to improve the retention of eyewear about the wearer's head have also included the use of rubber or rubber-like plastic boots applied to the free ends of the temples for increasing the friction between the eyeglasses and the head, such as shown in Bates U.S. Pat. No. 3,684,356. The Bates device, however, appears somewhat clumsy and awkward and, therefore, detracts from the appearance of the eyewear. In addition, the Bates device is limited in that it may not be adjusted relative to the eyewear; that is, the closed end of the boot prevents forward adjustment to a more anterior point of contact between the temples and the head, while an unsupported length of boot extending beyond the earpiece is undesirable.
Another prior attempt to improve eyewear retention is disclosed in the Nelson patent (U.S. Pat. No. 2,561,402), which discloses use of relatively complicated fluid chambers at the interface of the free end of the temples and the head. Nelson uses the fluid chambers in an effort to evenly distribute pressure between the temple and the head. As the fluid chambers of Nelson are permanently affixed to the temple in a predetermined orientation, modification for specific individuals is unavailable. In addition, the fluid retained within the chambers adds an undesired weight to the eyewear. Further, even if the fluid chambers were removable, such removal would substantially alter the fit of the eyewear, rendering the eyewear substantially unwearable.
Notwithstanding the foregoing, there remains a need for providing a means of improving the compatibility of eyewear and the wearer so as to improve retention of the eyewear. Preferably, the eyewear retention means will enable one size to comfortably and securely fit a much larger population than can one size eyewear having the traditional ear hook.
A need also exists for a device which improves retention of eyewear without permanently altering the configuration of the eyewear. A further need exists for a retaining device which may be easily disengaged or recombined with the eyewear without drastically changing the functioning or the appearance of the eyewear. In addition to the functional requirements of the traction device, an aesthetic requirement exists so that the device may be employed as a portion of eye wear in either an unobtrusive or distinctive, but attractive, mode.